1. Field of the Disclosure
The present disclosure relates to a liquid crystal display device. The present disclosure also relates to a liquid crystal display device where deterioration such as a light leakage or a non-uniformity in luminance is prevented due to an open portion of a light shielding tape and a concave portion of a main frame and a method of fabricating the liquid crystal display device.
2. Discussion of the Related Art
As the information age progresses, display devices processing and displaying a large amount of information have been rapidly developed. Specifically, various flat panel displays (FPDs) such as a liquid crystal display (LCD) device, a plasma display panel (PDP) device, an organic light emitting diode (OLED) display devices and a field emission display (FED) device having a superior performance with a thin profile, a light weight, and a low power consumption have substituted for a cathode ray tube (CRT).
Among various FPDs, the LCD device has various features such as a high contrast ratio and superiority in displaying a moving image. The LCD device has been widely used, such as computer monitors or televisions.
Since the LCD device is a non-emissive type display device, an additional light source is required. Accordingly, a backlight unit including a light source is disposed under the liquid crystal panel and a light from the backlight unit is supplied to the liquid crystal panel. For example, one of a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL) and a light emitting diode (LED) may be used as the light source. Among various light sources, the LED has been widely used for its various features such as a small size, a low power consumption and a high reliability.
Since the light from the backlight unit is partially transmitted to a region other than a display region of the liquid crystal panel, a light shielding tape is required to prevent the light leakage.
FIG. 1 is a cross-sectional view showing a liquid crystal display device including a light shielding tape according to the related art, and FIGS. 2A and 2B are cross-sectional views showing deterioration in a liquid crystal display device according to the related art.
In FIG. 1, a liquid crystal display (LCD) device 10 includes a liquid crystal panel 11, a backlight unit 20, a main frame 30 and a light shielding tape 61. The liquid crystal panel 11 for displaying an image includes first and second substrates 12 and 14 facing and spaced apart from each other and a liquid crystal layer (not shown) between the first and second substrates 12 and 14. First and second polarizing plates (not shown) are formed on outer surfaces of the first and second substrates 12 and 14, respectively.
The backlight unit 20 for supplying a light is disposed under the liquid crystal panel 11. The backlight unit 20 includes a light source along at least one side of the main frame 30, a reflecting plate 25 of a white color or a silver color, a light guide plate 23 on the reflecting plate 25 and a plurality of optical sheets 21 on the light guide plate 23.
For example, the light source may include a light emitting diode (LED) assembly 29 and the LED assembly 29 may include a plurality of LEDs 29a spaced apart from each other and a flexible printed circuit board (FPCB) 29b where the plurality of LEDs 29a are mounted. The LED assembly 29 is fixed by a method such as adhesion so that the light from the plurality of LEDs 29a can be emitted toward an incident surface of the light guide plate 23.
Since the LED assembly 29 is disposed at a side of the light guide plate 23 and the reflecting plate 25 is disposed under the light guide plate 23, the light from the plurality of LEDs 29a passes through a lower surface of the light guide plate 23 and is reflected on the reflecting plate 25 toward the liquid crystal panel 11. As a result, a luminance of the light supplied to the liquid crystal panel 11 increases.
The light guide plate 23 supplies a plane light to the liquid crystal panel 11 using the light from the plurality of LEDs 29a. 
The main frame 30 having a rectangular ring shape includes a flat portion 32 for supporting the LED assembly 29 and a guide wall 33 for guiding the LED assembly 29. The flat portion 32 is disposed inside the guide wall 33 and the guide wall 33 vertically protrudes from an edge portion of the main frame 30. The LED assembly 29 is disposed on the flat portion 32.
When the LCD device 10 is shown in a front view, the light shielding tape 61 is disposed to overlap an edge portion of the liquid crystal panel 11 and the main frame 30. In addition, the light shielding tape 61 is attached to a lower surface of the edge portion of the liquid crystal panel 11 and a top surface of the guide wall 33 of the main frame 30 so that the liquid crystal panel 11 and the backlight unit 20 can be modularized with the main frame 30 and the light shielding tape 61.
The main frame 30 wraps side surfaces of the backlight unit 20 to prevent disassembly of the backlight unit 20, and the light shielding tape 61 attaches and fixes the liquid crystal panel 11 to the main frame 30 to prevent disassembly of the liquid crystal panel 11. In addition, the light shielding tape 61 prevent a light leakage toward a region other than a display region of the liquid crystal panel 11.
Recently, as a demand for a thin profile of the LCD device 10 increases, a height of the guide wall 33 of the main frame 30 decreases. Since most of the modularization process for attaching the main frame 30 and the light shielding tape 61 is performed manually, it is hard to dispose the LED assembly 29 on the flat portion 32 of the main frame 30 accurately when the guide wall 33 has a relatively small height. Accordingly, when the LCD device 10 is modularized, decrease of the height of the guide wall 33 may cause deterioration such that the LED assembly 29 is disposed on the guide wall 33.
In FIG. 2A, when the LED assembly 29 is slantly disposed on the guide wall 33 during the modularization process, a light B1 emitted from the plurality of LEDs 29a of the LED assembly 29 is distorted to cause a light leakage. In FIG. 2B, when the LED assembly 29 is abnormally disposed on the guide wall 33 during the modularization process, a part B2 of a light emitted from the plurality of LEDs 29a directly enters the plurality of optical sheets 21 to cause non-uniformity in luminance of the plane light through the light guide plate 23.
In addition, as a width of the guide wall 33 decreases in the LCD device 10 of a thin profile, a contact area between the light shielding tape 61 and the guide wall 33 decreases and an adhesive force between the light shielding tape 61 and the guide wall 33 decreases. As a result, the light shielding tape 61 is detached from the main frame 30 and the detachment of the light shielding tape 61 causes a light leakage.
The LCD device 10 may be formed to have a relatively greater adhesion force by a relatively larger contact area between the light shielding tape 61 and the guide wall 33 or a relatively thicker adhesive layer of the light shielding tape 61. However, the larger contact area is limited due to design rule and the thicker adhesive layer is limited due to a thin light shielding tape 61.
In addition, even when the LED assembly 29 is disposed on the guide wall 33, the abnormal disposition is seldom detected with the naked eye during the modularization process for the LCD device 10 of a thin profile. Since the abnormal disposition of the LED assembly 29 and the guide wall 33 is detected after the modularization process is completed, fabrication process for rework is complicated and fabrication time and production cost of the LCD device 10 increase.